In conduit systems utilizing a plurality of lengths of tubular pipes or conduits, connector means must be provided for joining together the various lengths of tubing. Although connectors which engage the exterior surface of the tubing are well known, for some applications it is highly desirable to utilize a connector which engages the interior surfaces of the lengths of tubing being joined together. Exterior connectors are bulky and have outside diameters larger than the tubes. Additionally, for some applications, it is desirable that the internal diameter of the passageway defined by the interconnected lengths of tubing and the connector internal surface be substantially uniform. The desirability of having an uniform diameter passageway for the joined lengths of tubing and connector is particularly strong for joined tubes forming part of a fluid supply system or a system where wires or fiber optic bundles are passed through. Prior art conduit systems utilizing the "interior surface engagement" type of connector for joining adjacent lengths of tubing result in a passageway constriction which restricts the flow of fluid.
It is also important that the connector or coupler in combination with joined lengths of tubing meet certain minimum pull strength requirements. For some applications, such as joined lengths of tubing having fiber optic bundles passed therethrough using high speed air blowing systems, it is desirable that the joined lengths of tubing be capable of withstanding a predetermined amount of pressure with no significant loss of pressure.